BULLETIN No. 526 Contribution from the Bureau of Plant Industry Washington, D. C. WM. A. TAYLOR, Chief PROFESSIONAL PAPER August 28, 1918 IMPORTANCE OF SINGLE-STALK COTTON CULTURE. Single-stalk cotton culture was first announced as a new system in 1913, and at that time also its principles were outlined. Since that year three additional publications have been issued, which present results obtained in 1913 and 1914 from experiments with the system in Virginia, South Carolina, and Texas. The purpose of this report is to present the results obtained in 1915 from a series of experiments conducted in the States of Louisiana, Arkansas, and The single-stalk system is based on the recognition of a fact that has not been taken into practical account in most of the cultural Cook, O. F. Single-stalk cotton culture. U. S. Dept Agr., Bur. Plant Indus. [Misc. Pub.] 1130, 11 experiments that have been made with cotton, namely, that the cotton plant has two distinct kinds of branches, vegetative and fruiting, and that the relative growth of these can be controlled by cultural methods. Single-stalk cotton culture differs from systems usually employed in two essential features, namely, the time of thinning and the spacing of plants in the row. Where the usual methods involve thinning the seedlings soon after complete germination and spacing to distances varying with the locality from 12 to 30 or more inches, single-stalk culture involves later thinning and closer spacing, down to 6 inches, or even less under some conditions. The purpose of the later thinning is to suppress the development of vegetative branches, which usually are produced at the lower nodes of the main stalk. If cotton plants are left close together in the row during the early stages of their growth, few vegetative branches are likely to develop, for the buds at the lower nodes of the main stalks remain dormant, and only fruiting branches appear at the upper nodes. So in applying single-stalk culture, thinning is delayed until after the suppression of vegetative branches has been accomplished and until fruiting branches are expected to appear. Then the plants are spaced only far enough apart to allow for the normal development of the fruiting branches. The distance at which single-stalk plants may be spaced to advantage will depend upon local conditions, differing with soil and climate and the variety used, but, owing to their narrow, erect form the plants may be left much closer together than usual without danger of injurious crowding. In fact, singlestalk rows usually are less crowded than those in which the plants, thinned early and wide spaced, have been allowed to develop fully their long basal limbs, which often equal or even exceed in size the main stalk of the plant. Owing to the suppression of excessive vegetative growth on singlestalk plants, they usually reach maturity in a shorter time than the more bushy plants. While fewer bolls per plant may be produced, single-stalk rows usually contain a greater total number of bolls and hence give larger row yields than rows grown by the usual systems of culture. Another important feature of single-stalk culture is that, where later thinning is practiced, greater protection is afforded against damage from inclement weather or other injuries to which the seedlings are subject, particularly leaf-cut or tomosis.1 An additional advantage of later thinning lies in the opportunity to take out weak or injured plants when the thinning is done, so that only normal individuals are left, a condition which increases the yield and earliness of the crop. 1 Cook, O. F. Leaf-cut, or tomosis, a disorder of cotton seedlings. In U. S. Dept. Agr., Bur. Plant Indus. Cir. 120, p. 29-34, 1 fig. 1913. The success attained in early experiments with single-stalk culture led to a belief that it should prove advantageous under a variety of conditions existing in the cotton belt. The idea of suppressing the vegetative branches was first developed and applied in connection with the production of Egyptian cotton in the Southwest, where it proved to be of distinct value in checking the rank growth of the plants, which for a time threatened the success of the industry.1 Later, at Norfolk, Va., where the season is relatively short, singlestalk culture gave significantly larger and distinctly earlier yields than the older methods with which it was compared. Similar results have since been obtained in South Carolina with both Sea Island and Upland cotton, and also in Texas, where the most striking advantages have been shown under extreme conditions both of drought and of weevil infestation. These early experiments showed that the system could be used to advantage under a very wide range of conditions, but a large amount of experimental work still remains to be done in order to determine how to secure the best results with the system under any given combination of local conditions of soil, season, and variety of cotton. The results of these experiments indicate that single-stalk culture may be profitably applied under a wide range of natural conditions, but definite recommendations can not be made for all localities, as it is recognized that a thorough knowledge of local conditions and familiarity with the new system are essential to its successful application. It is not expected that experiments with the new system will show advantages under all conditions, and in some instances unfavorable results may be secured, as has been recorded by the Bureau of Entomology in connection with tests conducted by that Bureau in Louisiana in 1915. Such cases may enable the experimenter to understand the nature and practical limitations of the system and to determine under what conditions of climate, soil, etc., it may be a desirable method for the cotton grower to adopt. LOCALITIES WHERE EXPERIMENTS WERE MADE. The present experiments were located in the States of Louisiana, Arkansas, and North Carolina. The parishes and counties in which the work was done, the farmers conducting the experiments, their post-office addresses, and the agents cooperating are listed in Table I. 1 For a general statement of the cultural difficulties encountered and the means employed in surmounting them, see Scofield, C. S., Kearney, T. H., Brand, C. J., Cook, O. F., and Swingle, W. T., Community production of Egyptian cotton in the United States, U. S. Dept. Agr. Bul. 332, 30 p. 1916. |